1. Field of the Invention
This invention relates to systems for monitoring specific patient parameters and more particularly to systems which monitor electrocardiogram (ECG) waveforms and respiration waveforms, and which are designed to provide output signals which have a controlled amplitude and baseline.
2. Discussion of Related Art
Monitoring of specific patient parameters on a continuing basis is becoming a generally accepted diagnostic tool. This is particularly true in the case of infants which are deemed "at risk" and susceptible to sudden infant death syndrome. Such infants exhibit prolonged apnea and bradycardia episodes. Apnea is defined as the cessation of respiration, and bradycardia is defined as low heart rate
A presently available monitor is a Model 16000 Infant Monitor manufactured and sold by Healthdyne, Inc., of Marietta, Ga. This infant monitor is designed to manage infants who have been determined to be at risk by providing signals indicative of the infant's respiration and heart activity. The monitor contains two control adjustments which must be made by the operator to properly set up the unit. These controls are for the sensitivity setting of the respiration and ECG channels. The monitor provides excellent operation when the sensitivity settings are proper. However, it is possible for people to poorly adjust the sensitivity settings and in so doing cause signal dropouts and accompanying false alarms. Accordingly, a need has developed for a monitor which automatically controls the sensitivity of the respiration and ECG signals.
The present invention can be used in combination with a recorder to provide a visual display of the monitored parameters. Such a recorder is disclosed in U.S. application Ser. No. 383,296, filed May 28, 1982, and in a continuation-in-part of Ser. No. 383,296, which applications are incorporated by reference herein.